1530 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 3 



swamps with standing water and with brushy thickets such as mesquite 

 or rose in the immediate dry-land surroundings. Both the thickets 

 and the cattails are frequented by the Song Sparrows, the latter 

 being resorted to especially for greater protection * * *. Bird as- 

 sociates are Marsh Wrens, Yellow-throats, Yellow Warblers, and 

 Red-winged Blackbirds * * *. The swamps where these birds do 

 occur are few in number and widely scattered. If the swamps are 

 of any extent at all, Song Sparrows are numerous in them, but the 

 total * * * population cannot be great. This spotty distribution of 

 suitable swampy habitat * * * makes for discontinuous distribution 

 of the colonies within the general range of the race." 



Nesting. — The nesting habits of fallax are similar to those of other 

 populations in more temperate areas. The nest is always built close 

 to open water. Francis C. Willard (1912) found a nest in a low bush. 

 The same author (1923) writes "The Song Sparrow sometimes deserts 

 the ground and low bushes in favor of a tree, and the desert subspecies 

 (Melospiza melodia fallax) also has this trait. One nest was built 

 fifteen feet up in a large willow tree, on a horizontal branch. The 

 bird was on the nest when I found it and remained until I was nearly 

 up to it. * * * There were four of the song sparrow's eggs and four 

 of the Long-tailed Chat * * *." 



Herbert Brandt (1951) describes the site of a nest he found on the 

 Slaughter (San Bernadino) Ranch 20 miles east of Douglas, Cochise 

 County, Ariz., in an "irrigation project near cattail pond in grassy 

 meadow; surrounding flora, small mesquites, sacaton and other 

 grasses, beyond which are rows of black willow and cottonwood, and 

 in near-by pond, cattails and other water plants; date, May 23, 1948. 

 Nest situated 18 inches up in a low dense mesquite brush, 25 feet 

 from artesian pond rim; nest placed in a four-pronged fork of dead 

 wood; made in a crude, bulky manner of coarse plant stems and 

 leaves; rim substantial but ragged and irregular, shaped to fit the 

 supports; lining of brown rootlets and white cow-tail hair arranged 

 circularly; interior well cupped. Apparently the only pair present 

 in the area. Contents, 3 eggs, unevenly incubated 6 to 8 days." 

 A female taken March 26 near La Casita (27 miles south of Nogales, 

 Sonora) contained ova measuring 7 and 4 millimeters. Full grown 

 young have been collected by May 30 (Feldman, San Pedro River). 



Eggs. — There are 15 sets of eggs of fallax in the United States Na- 

 tional Museum and one set in the University of Arizona collection. 

 These sets contain 2, 3, and 4 eggs, with 3 being the most frequent 

 number and the average. These eggs measure in millimeters 14.1 to 

 15.7 by 17.4 to 21.7. The average of the 48 eggs is 15.00 by 19.03. 



Plumages. — The molts and plumages of the desert populations are 

 similar to those of the species elsewhere, save for the light coloration 



